Abstract Data-driven tools, such as principal component analysis (PCA) and independent component analysis (ICA) have been applied to different benchmarks as process monitoring methods. The difference between the t...Abstract Data-driven tools, such as principal component analysis (PCA) and independent component analysis (ICA) have been applied to different benchmarks as process monitoring methods. The difference between the two methods is that the components of PCA are still dependent while ICA has no orthogonality constraint and its latentvariables are independent. Process monitoring with PCA often supposes that process data or principal components is Gaussian distribution. However, this kind of constraint cannot be satisfied by several practical processes. To ex-tend the use of PCA, a nonparametric method is added to PCA to overcome the difficulty, and kernel density estimation (KDE) is rather a good choice. Though ICA is based on non-Gaussian distribution intormation, .KDE can help in the close monitoring of the data. Methods, such as PCA, ICA, PCA.with .KDE(KPCA), and ICA with KDE,(KICA), are demonstrated and. compared by applying them to a practical industnal Spheripol craft polypropylene catalyzer reactor instead of a laboratory emulator.展开更多
It has been introduced several ways for rising fuel burning rate. Using catalyzers is a common way to rising fuel burning rate. Cu-Chromite catalyzer used in solid fuels, as burning rate catalyzer in thermal decomposi...It has been introduced several ways for rising fuel burning rate. Using catalyzers is a common way to rising fuel burning rate. Cu-Chromite catalyzer used in solid fuels, as burning rate catalyzer in thermal decomposition of Ammonium Perchlorate and results were satisfying. This catalyzer is produced by several methods such as: ceramic, coprecipitating, sol-gel, vacuum depositioning, but this paper explains producing catalyzer by Citrate sol-gel. Thermal analysis is used for studying process also SEM, XRD, TEM, FTIR tests used for determination of particle sizes.展开更多
The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporat...The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was reported.Outstanding hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mV at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) samples.In the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co sites.It was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 V at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting voltage.It was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation.展开更多
This article looks for the necessary conditions to use Deuterium-Deuterium (D-D) fusion for a large power plant. At the moment, for nearly all the projects (JET, ITER…) only the Deuterium-Tritium (D-T) fuel is consid...This article looks for the necessary conditions to use Deuterium-Deuterium (D-D) fusion for a large power plant. At the moment, for nearly all the projects (JET, ITER…) only the Deuterium-Tritium (D-T) fuel is considered for a power plant. However, as shown in this article, even if a D-D reactor would be necessarily much bigger than a D-T reactor due to the much weaker fusion reactivity of the D-D fusion compared to the D-T fusion, a D-D reactor size would remain under an acceptable size. Indeed, a D-D power plant would be necessarily large and powerful, i.e. the net electric power would be equal to a minimum of 1.2 GWe and preferably above 10 GWe. A D-D reactor would be less complex than a D-T reactor as it is not necessary to obtain Tritium from the reactor itself. It is proposed the same type of reactor yet proposed by the author in a previous article, i.e. a Stellarator “racetrack” magnetic loop. The working of this reactor is continuous. It is reminded that the Deuterium is relatively abundant on the sea water, and so it constitutes an almost inexhaustible source of energy. Thanks to secondary fusions (D-T and D-He3) which both occur at an appreciable level above 100 keV, plasma can stabilize around such high equilibrium energy (i.e. between 100 and 150 keV). The mechanical gain (Q) of such reactor increases with the internal pipe radius, up to 4.5 m. A radius of 4.5 m permits a mechanical gain (Q) of about 17 which thanks to a modern thermo-dynamical conversion would lead to convert about 21% of the thermal power issued from the D-D reactor in a net electric power of 20 GWe. The goal of the article is to create a physical model of the D-D reactor so as to estimate this one without the need of a simulator and finally to estimate the dimensions, power and yield of such D-D reactor for different net electrical powers. The difficulties of the modeling of such reactor are listed in this article and would certainly be applicable to a future D-He3 reactor, if any.展开更多
The behavior of antimony oxidation in the solution of sodium thioantimonite was studied in the presence of catalytic agents. The catalytic effects of the respective addition of cupric sulfate, sodium tartrate, potassi...The behavior of antimony oxidation in the solution of sodium thioantimonite was studied in the presence of catalytic agents. The catalytic effects of the respective addition of cupric sulfate, sodium tartrate, potassium permanganate, phenol, 1,2 dihydroxybenzene and their combination on the oxidation of sodium thioantimonite were investigated. A pilot test was carried out. The results show that the respective use of sodium tartrate, cupric sulfate, potassium permanganate, phenol and 1,2 dihydroxybenzene have little catalytic effect on the oxidation of sodium thioantimonite. However there exists obvious catalytic oxidation by the combination of 0.25 g/L 1,2 dihydroxybenzene, 0.5 g/L potassium permanganate and 1.0 g/L phenol. Moreover, high blast intensity, the increase of temperature and NaOH concentration favor the oxidation of antimony. The oxidation process of antimony has such advantages as quick reaction and low operation costs. The results of the pilot test are consistent with those of laboratory experiments.展开更多
The secondary reinforcement,crbon whiskers,may grow on the surface of parent rein- forcement,carbon fibres,by chemical vapour growth from acetylene using Fe salt as catalyzer.The optimal growing temperature is about 1...The secondary reinforcement,crbon whiskers,may grow on the surface of parent rein- forcement,carbon fibres,by chemical vapour growth from acetylene using Fe salt as catalyzer.The optimal growing temperature is about 1000℃,and while the concentra- tion of catalytic solution is appropriate,the carbon whiskers may deposite uniformly and link each other on the parent carbon fibre surface.If the temperature or concentration is too high,the coarse clusters of carbon may deposite on the fibre surface.The mechanism of carbon whisker growth is believed that the carbon atoms in vapour phase dissolve in the Fe salt drops over fibres,then the solid carbon grains precipitate on the fibre surface.展开更多
Effects of the KCI additions (1%, 3%, 5% and 7% of the phenolic resin mass ) on phase composition and microstructure of the resin carbon and the growth mechanism of carbon fibers were investigated by using commercia...Effects of the KCI additions (1%, 3%, 5% and 7% of the phenolic resin mass ) on phase composition and microstructure of the resin carbon and the growth mechanism of carbon fibers were investigated by using commercial liquid phenolic resin as carbon source and micron-scaled KCl us catalyzer, mixing, hexamethylene- tetramine solidification treating, carbon-embedded firing at 1 000 ℃ for 3 h in order to accelerate the graphitization of phenolic resin during carbonization. The results show that the graphitization degree of resin carbon is im- proved by catalysis of KCl, numerous carbon fibers with 30 - 200 nm in diameter and 10 - 20 μm in length and sheet-like carbon in situ grow in resin carbon. The opti- mal addition of KCl is 5% when lots of carbon fibers can be found in resin carbon, and doo2 diffraction peak of graphite appears obviously in the XRD pattern. The growth mechanism of carbon fiber is that the molten KCl at high temperatures absorbs carbonaceous gas from the decomposition of phenolic resin, accelerating the diffu- sion of solid C atoms in liquid KCl ; after the dissolution of C saturates, carbon atoms separate continuously in lo- cal parts to form carbon fibers or flakes ; meanwhile, the concentration gradient formed by local carbon atoms in the melt offers growth drive for the separation of carbon fibers or flakes on KCl surface.展开更多
Conjugated linoleic acid (CLA) is a fatty acid with physiological activities and potential application prospect. This paper focuses on the method of synthesis of conjugated linoleic acid of high purity and the process...Conjugated linoleic acid (CLA) is a fatty acid with physiological activities and potential application prospect. This paper focuses on the method of synthesis of conjugated linoleic acid of high purity and the process line and conditions for its purification that can be used in large scale production. CLA of more than 95% purity was prepared by means of urea adduct purification and conjugation using safflower oil as material. The total recovery of the product adds up to more than 48%. The reactive kinetics about linoleic acid from sunflower oil converted into CLA was investigated, and its apparent kinetic model was also established, which can be used as a base for industrial designs.展开更多
The single-walled carbon nanotube(SWNT) bundles and ropes have been prepared by using the anode are discharge plasma to evaporate the graphite rods which contain Fe, Co and Ni powders as catalyst in He atmosphere. M...The single-walled carbon nanotube(SWNT) bundles and ropes have been prepared by using the anode are discharge plasma to evaporate the graphite rods which contain Fe, Co and Ni powders as catalyst in He atmosphere. Many purifying methods are used for the products. It indicates that the synthesis of SWNTs has been greatly affected by the preparation parameters of catalyzer, the buffer gas and its pressure, the arc current intensity, etc. The optimal condition for preparing SWNTs in our case has been proposed. The forming mechanism of the SWNTs bundles and ropes is also studied qualitatively. The evaporated single graphite sheet tends to reduce its active energy.展开更多
This article briefly reviewed the advances in the process of the direct oxidation of methane to methanol (DMTM) with both heterogeneous and homogeneous oxidation. Attention was paid to the conversion of methane by t...This article briefly reviewed the advances in the process of the direct oxidation of methane to methanol (DMTM) with both heterogeneous and homogeneous oxidation. Attention was paid to the conversion of methane by the heterogeneous oxidation process with various transition metal ox‐ides. The most widely studied catalysts are based on molybdenum and iron. For the homogeneous gas phase oxidation, several process control parameters were discussed. Reactor design has the most crucial role in determining its commercialization. Compared to the above two systems, aque‐ous homogenous oxidation is an efficient route to get a higher yield of methanol. However, the cor‐rosive medium in this method and its serious environmental pollution hinder its widespread use. The key challenge to the industrial application is to find a green medium and highly efficient cata‐lysts.展开更多
Securing new sources of energy has become a major concern, because fossil fuels are expected to be depleted within several decades. In some of the major wars of the 20th century, control of oil was either a proximate ...Securing new sources of energy has become a major concern, because fossil fuels are expected to be depleted within several decades. In some of the major wars of the 20th century, control of oil was either a proximate cause or a decisive factor in the outcome. Especially in Japan and Germany, a great deal of research was devoted to making liquid fuels from coal. In one such experiment, a large amount of excess heat was observed. The present study was devoted to replicating and controlling that excess heat effect. The reactant is phenanthrene, a heavy oil fraction, which is subjected to high pressure and high heat in the presence of a metal catalyst. This results in the production of excess heat and strong penetrating electromagnetic radiation. After the reaction, an analysis of residual gas reveals a variety of hydrocarbons, but it seems unlikely that these products can explain the excess heat. Most of them form endothermically, and furthermore heat production reached 60 W. Overall heat production exceeded any conceivable chemical reaction by two orders of magnitude.展开更多
Neutral isotopes and ions of H, He and Li define the chemistry of the early universe by collisional and radiative process, where under low temperature and radiation regime, only neutral species were essential in the c...Neutral isotopes and ions of H, He and Li define the chemistry of the early universe by collisional and radiative process, where under low temperature and radiation regime, only neutral species were essential in the cooling mass that gave origin to the first proto star structures. Nevertheless, up to now, in every kinetic model Li is permanently discarded from fundamental reactions due to its extremely low density. Contrarily to these previous models we have developed a novel kinetic model based on two consecutive reactions of Li and LiH with H, in order to generate a recursive process that fit well H2 production to temperatures as low as 200 K, according to the cosmological time at the end of the dark epoch. Our results show how Li and LiH merge as first catalyzers of the H to H2 chemical reaction and permit us to explain the expected abundance of H2 as the main coolant in the early universe as well as in cold regions of the cosmos.展开更多
The dectrochemical reduction characteristics of carbon tetrachlofide (CT) were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders'...The dectrochemical reduction characteristics of carbon tetrachlofide (CT) were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders' iron and the catalyzed Fe-Cu process was discussed. The results showed that CT was reduced directly on the surface of copper rather than by atomic hydrogen produced at the cathode in the catalyzed Fe-Cu process. The reduction was realized largely by atomic hydrogen in Master Builders' iron. The entire CT in 350 ml aqueous solution with 320 mg/L was reduced to trichloromethane and dichloromethane in 2.25 h when 100 g of scrap iron with Fe/Cu ratio of 10:1 (w/w) were used. Moreover, the reduction rate slowed with time. CT could be reduced at acidic, neutral and alkaline pH from solution by Fe-Cu bimetallic media, but the mechanisms were different. The degradation rate was not significantly influenced by pH in the catalyzed Fe-Cu process; in Master Builders' iron it clearly increased with decreasing pH. The kinetics of the reductions followed pseudo-first order in both cases. Furthermore, the reductions under acidic conditions proceeded faster than that under the neutral and alkaline conditions. The catalyzed Fe-Cu process was superior to Master Builders' iron in treating CT-containing water and this advantage was particularly noticeable under alkaline conditions. The reduction was investigated in the cathode (Cu) and anode (Fe) compartments respectively, the results showed that the direct reduction pathway played an important role in the reduction by the catalyzed Fe-Cu process. The catalyzed Fe-Cu process is of practical value.展开更多
A novel technology which combined electrochemical process catalyzed by manganese mineral with electro-assisted coagulation process was proposed in this study. The mineralization of organic pollutant from simulated dye...A novel technology which combined electrochemical process catalyzed by manganese mineral with electro-assisted coagulation process was proposed in this study. The mineralization of organic pollutant from simulated dye wastewater containing an azo dye Acid Red B(ARB) was experimentally investigated using this method. It was found that the manganese mineral could catalyze the electrochemical process dramatically. The TOC removal percentage of electrochemical treatment catalyzed by manganese mineral was 43.6% while the TOC removal percentage of the process using the manganese mineral alone and using the electrolysis alone were 9.3% and 20.8%, respectively. Moreover, it was found that combined electroxidation with electro-assisted coagulation process could more effectively eliminate ARB. After a period of 180 min electrooxidation and 300 min electroreduction, almost 66.9% of TOC was removed, and the dissolved Mn^2+. could be effectivly removed. The effects of the order of oxidation and reduction, the proper ratio electrooxidation/reduction time, and current density on the removal efficiency were investigated in detail. In addition, a proposed mechanism of manganese-mineral-catalyzed electrooxidation-reduction process was discussed in this paper.展开更多
The reduction of the nitrobenzene compounds (NBCs) by the catalyzed Fe-Cu process and the relationship between the electrochemical reduction characteristics of NBCs at copper electrode and reduction rate were studie...The reduction of the nitrobenzene compounds (NBCs) by the catalyzed Fe-Cu process and the relationship between the electrochemical reduction characteristics of NBCs at copper electrode and reduction rate were studied in alkaline medium(pH=11). The catalyzed Fe-Cu process was found more effective on degradation of NBCs compared to Master Builder's iron. The reduction rate by the catalyzed Fe-Cu process decreased in the following order: nitrobenzene 〉4-chloro-nitrobenzene ≥m-dinitrobenzene :〉 4-nitrophenol ≥2,4-dinitrotoluene 〉2-nitrophenol. The reduction rate by Master Builder's iron decreased in the following order: m-dinitrobenzene ≥4-chloro-nitrobenzene 〉4-nitrophenol 〉2,4-dinitrotoluene ≈nitrobenzene 〉2-nitrophenol. NBCs were reduced directly on the surface of copper rather than by the hydrogen produced at cathode in the catalyzed Fe-Cu process. The reduction was realized by the hydrogen produced at cathode and Fe(OH)2 in Master Builder's iron, It is an essential difference in reaction mechanisms between these two technologies. For this reason, the reduction by the catalyzed Fe-Cu depended greatly on NBC's electron withdrawing ability.展开更多
Forced oxidation of calcium sulfite aqueous slurry is a key step for the calcium-based flue gas desulfurization(FGD) residue. Experiments were conducted in a semi-batch system and a continuous flow system on lab scale...Forced oxidation of calcium sulfite aqueous slurry is a key step for the calcium-based flue gas desulfurization(FGD) residue. Experiments were conducted in a semi-batch system and a continuous flow system on lab scales. The main reactor in semi-batch system is a 1000 ml volume flask. It has five necks for continuous feeding of gas and a batch of calcium sulfite solution/aqueous slurry. In continuous flow system, the main part is a jacketed Pyrex glass reactor in which gas and solution/aqueous slurry are fed continuously. Calcium sulfite oxidation is a series of complex free-radical reactions. According to experimental results and literature data, the reactions are influenced significantly by manganese as catalyst. At low concentration of manganese and calcium sulfite, the reaction rate is dependent on 1.5 order of sulfite concentration, 0.5 order of manganese concentration, and zero order of oxygen concentration in which the oxidation is controlled by chemical kinetics. With concentrations of calcium sulfite and manganese increasing, the reactions are independent gradually on the constituents in solution but are impacted by oxygen concentration. Manganese can accelerate the free-radical reactions, and then enhances the mass transfer of oxygen from gas to liquid. The critical concentration of calcium sulfite is 0.007 mol/L, manganese is 10 -4 mol/L, and oxygen is of 0.2—0.4 atm.展开更多
Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves ...Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves high activation energy and could render high burning rate regime.This study reports on the sustainable fabrication of CuO nanoparticles as a novel catalyzing agent for APC oxidizer.Colloidal CuO nanoparticles with consistent product quality were fabricated by using hydrothermal processing.TEM micrographs demonstrated mono-dispersed particles of 15 nm particle size.XRD diffractogram demonstrated highly crystalline material.The synthesized colloidal CuO particles were effectively coated with APC particles via co-precipitation by using fast-crash solvent-antisolvent technique.The impact of copper oxide particles on APC thermal behavior has been investigated using DSC and TGA techniques.APC demonstrated an initial endothermic decomposition stage at 242℃ with subsequent two exothermic decomposition stages at 297,8℃ and 452.8℃ respectively.At 1 wt%,copper oxide offered decrease in initial endothermic decomposition stage by 30%.The main outcome of this study is that the two main exothermic decomposition peaks were merged into one single peak with an increase in total heat release by 53%.These novel features can inherit copper oxide particles unique catalyzing ability for advanced highly energetic systems.展开更多
In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SOH-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high...In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SOH-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high catalytic activity and reusability with good to excellent yields of the desired products.Hammett method has been used to determine the acidity order of these ionic liquids and the results are consistent with the catalytic activities observed in acetalization reaction.Maximum product yield of 93%was observed on using[PSPy][OTf]as catalyst and it can be reused at least 8 times without obvious activity loss.展开更多
The mechanism of oxygen pressure acid leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation was investigated in this study.Artificial sphalerite was fabricated with varying amounts of iron content via the ...The mechanism of oxygen pressure acid leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation was investigated in this study.Artificial sphalerite was fabricated with varying amounts of iron content via the sintering of ZnS and FeS and used for the pressure acid leaching experiment.The variations in the potential of the pressure leaching system were investigated by using a self-designed potential autoclave.The results showed that compared to the non-iron sphalerite,there was a violent redox reaction between the 25.70%Fe-artificial sphalerite and dissolved oxygen during the process of pressure leaching;and the catalytic mechanism was attributed to the redox couple Fe^3+/Fe^2+,where Fe3+oxidizes the H2S gas film and the reduced Fe2+state is subsequently oxidized by the dissolved oxygen.Furthermore,the effect of temperature,H2SO4 concentration,and oxygen partial pressure on the artificial sphalerite with different iron contents was studied.The sphalerite samples with iron content were observed to dissolve more easily in sulfuric acid compared to the non-iron samples.Moreover,the activation energy of artificial sphalerite was observed to be lower in the sample with 25.70%iron content(22.26 kJ/mol)compared to that with no iron(32.31 kJ/mol);and the apparent reaction orders were obtained with respect to H2SO4 concentration(1.10 and 1.36)and oxygen partial pressure(1.29 and 1.41),respectively.A comprehensive kinetic model was developed on the basis of the experimental data and the fitted leaching ratio plot;and the kinetic equations for the leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation were determined.展开更多
基金Supported by the National Natural Science Foundation of China (No.60574047) and the Doctorate Foundation of the State Education Ministry of China (No.20050335018).
文摘Abstract Data-driven tools, such as principal component analysis (PCA) and independent component analysis (ICA) have been applied to different benchmarks as process monitoring methods. The difference between the two methods is that the components of PCA are still dependent while ICA has no orthogonality constraint and its latentvariables are independent. Process monitoring with PCA often supposes that process data or principal components is Gaussian distribution. However, this kind of constraint cannot be satisfied by several practical processes. To ex-tend the use of PCA, a nonparametric method is added to PCA to overcome the difficulty, and kernel density estimation (KDE) is rather a good choice. Though ICA is based on non-Gaussian distribution intormation, .KDE can help in the close monitoring of the data. Methods, such as PCA, ICA, PCA.with .KDE(KPCA), and ICA with KDE,(KICA), are demonstrated and. compared by applying them to a practical industnal Spheripol craft polypropylene catalyzer reactor instead of a laboratory emulator.
文摘It has been introduced several ways for rising fuel burning rate. Using catalyzers is a common way to rising fuel burning rate. Cu-Chromite catalyzer used in solid fuels, as burning rate catalyzer in thermal decomposition of Ammonium Perchlorate and results were satisfying. This catalyzer is produced by several methods such as: ceramic, coprecipitating, sol-gel, vacuum depositioning, but this paper explains producing catalyzer by Citrate sol-gel. Thermal analysis is used for studying process also SEM, XRD, TEM, FTIR tests used for determination of particle sizes.
基金the financial support of the Doctoral Research Initiation Foundation of Linyi University(LYDX2020BS016)the National Natural Science Foundation of Shandong Province(ZR2021QB208,ZR2022MB054)+4 种基金the National Natural Science Foundation of China(22305262)SIAT Innovation Program for Excellent Young Researchers(2022)Shenzhen Science and Technology Program Grant(RCJC20200714114435061,ZDSYS20220527171406014)the City University of Hong Kong Donation Research Grants(9220061 and 9229021)City University of Hong Kong Strategic Research Grant(SRG 7005505)。
文摘The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was reported.Outstanding hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mV at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) samples.In the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co sites.It was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 V at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting voltage.It was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation.
文摘This article looks for the necessary conditions to use Deuterium-Deuterium (D-D) fusion for a large power plant. At the moment, for nearly all the projects (JET, ITER…) only the Deuterium-Tritium (D-T) fuel is considered for a power plant. However, as shown in this article, even if a D-D reactor would be necessarily much bigger than a D-T reactor due to the much weaker fusion reactivity of the D-D fusion compared to the D-T fusion, a D-D reactor size would remain under an acceptable size. Indeed, a D-D power plant would be necessarily large and powerful, i.e. the net electric power would be equal to a minimum of 1.2 GWe and preferably above 10 GWe. A D-D reactor would be less complex than a D-T reactor as it is not necessary to obtain Tritium from the reactor itself. It is proposed the same type of reactor yet proposed by the author in a previous article, i.e. a Stellarator “racetrack” magnetic loop. The working of this reactor is continuous. It is reminded that the Deuterium is relatively abundant on the sea water, and so it constitutes an almost inexhaustible source of energy. Thanks to secondary fusions (D-T and D-He3) which both occur at an appreciable level above 100 keV, plasma can stabilize around such high equilibrium energy (i.e. between 100 and 150 keV). The mechanical gain (Q) of such reactor increases with the internal pipe radius, up to 4.5 m. A radius of 4.5 m permits a mechanical gain (Q) of about 17 which thanks to a modern thermo-dynamical conversion would lead to convert about 21% of the thermal power issued from the D-D reactor in a net electric power of 20 GWe. The goal of the article is to create a physical model of the D-D reactor so as to estimate this one without the need of a simulator and finally to estimate the dimensions, power and yield of such D-D reactor for different net electrical powers. The difficulties of the modeling of such reactor are listed in this article and would certainly be applicable to a future D-He3 reactor, if any.
文摘The behavior of antimony oxidation in the solution of sodium thioantimonite was studied in the presence of catalytic agents. The catalytic effects of the respective addition of cupric sulfate, sodium tartrate, potassium permanganate, phenol, 1,2 dihydroxybenzene and their combination on the oxidation of sodium thioantimonite were investigated. A pilot test was carried out. The results show that the respective use of sodium tartrate, cupric sulfate, potassium permanganate, phenol and 1,2 dihydroxybenzene have little catalytic effect on the oxidation of sodium thioantimonite. However there exists obvious catalytic oxidation by the combination of 0.25 g/L 1,2 dihydroxybenzene, 0.5 g/L potassium permanganate and 1.0 g/L phenol. Moreover, high blast intensity, the increase of temperature and NaOH concentration favor the oxidation of antimony. The oxidation process of antimony has such advantages as quick reaction and low operation costs. The results of the pilot test are consistent with those of laboratory experiments.
文摘The secondary reinforcement,crbon whiskers,may grow on the surface of parent rein- forcement,carbon fibres,by chemical vapour growth from acetylene using Fe salt as catalyzer.The optimal growing temperature is about 1000℃,and while the concentra- tion of catalytic solution is appropriate,the carbon whiskers may deposite uniformly and link each other on the parent carbon fibre surface.If the temperature or concentration is too high,the coarse clusters of carbon may deposite on the fibre surface.The mechanism of carbon whisker growth is believed that the carbon atoms in vapour phase dissolve in the Fe salt drops over fibres,then the solid carbon grains precipitate on the fibre surface.
文摘Effects of the KCI additions (1%, 3%, 5% and 7% of the phenolic resin mass ) on phase composition and microstructure of the resin carbon and the growth mechanism of carbon fibers were investigated by using commercial liquid phenolic resin as carbon source and micron-scaled KCl us catalyzer, mixing, hexamethylene- tetramine solidification treating, carbon-embedded firing at 1 000 ℃ for 3 h in order to accelerate the graphitization of phenolic resin during carbonization. The results show that the graphitization degree of resin carbon is im- proved by catalysis of KCl, numerous carbon fibers with 30 - 200 nm in diameter and 10 - 20 μm in length and sheet-like carbon in situ grow in resin carbon. The opti- mal addition of KCl is 5% when lots of carbon fibers can be found in resin carbon, and doo2 diffraction peak of graphite appears obviously in the XRD pattern. The growth mechanism of carbon fiber is that the molten KCl at high temperatures absorbs carbonaceous gas from the decomposition of phenolic resin, accelerating the diffu- sion of solid C atoms in liquid KCl ; after the dissolution of C saturates, carbon atoms separate continuously in lo- cal parts to form carbon fibers or flakes ; meanwhile, the concentration gradient formed by local carbon atoms in the melt offers growth drive for the separation of carbon fibers or flakes on KCl surface.
文摘Conjugated linoleic acid (CLA) is a fatty acid with physiological activities and potential application prospect. This paper focuses on the method of synthesis of conjugated linoleic acid of high purity and the process line and conditions for its purification that can be used in large scale production. CLA of more than 95% purity was prepared by means of urea adduct purification and conjugation using safflower oil as material. The total recovery of the product adds up to more than 48%. The reactive kinetics about linoleic acid from sunflower oil converted into CLA was investigated, and its apparent kinetic model was also established, which can be used as a base for industrial designs.
文摘The single-walled carbon nanotube(SWNT) bundles and ropes have been prepared by using the anode are discharge plasma to evaporate the graphite rods which contain Fe, Co and Ni powders as catalyst in He atmosphere. Many purifying methods are used for the products. It indicates that the synthesis of SWNTs has been greatly affected by the preparation parameters of catalyzer, the buffer gas and its pressure, the arc current intensity, etc. The optimal condition for preparing SWNTs in our case has been proposed. The forming mechanism of the SWNTs bundles and ropes is also studied qualitatively. The evaporated single graphite sheet tends to reduce its active energy.
基金supported by the Petrochemical Joint Funds of NSFC-CNPC (U1362202)the Postgraduate Innovation Project of China University of Petroleum (East China) (YCXJ2016030)~~
文摘This article briefly reviewed the advances in the process of the direct oxidation of methane to methanol (DMTM) with both heterogeneous and homogeneous oxidation. Attention was paid to the conversion of methane by the heterogeneous oxidation process with various transition metal ox‐ides. The most widely studied catalysts are based on molybdenum and iron. For the homogeneous gas phase oxidation, several process control parameters were discussed. Reactor design has the most crucial role in determining its commercialization. Compared to the above two systems, aque‐ous homogenous oxidation is an efficient route to get a higher yield of methanol. However, the cor‐rosive medium in this method and its serious environmental pollution hinder its widespread use. The key challenge to the industrial application is to find a green medium and highly efficient cata‐lysts.
文摘Securing new sources of energy has become a major concern, because fossil fuels are expected to be depleted within several decades. In some of the major wars of the 20th century, control of oil was either a proximate cause or a decisive factor in the outcome. Especially in Japan and Germany, a great deal of research was devoted to making liquid fuels from coal. In one such experiment, a large amount of excess heat was observed. The present study was devoted to replicating and controlling that excess heat effect. The reactant is phenanthrene, a heavy oil fraction, which is subjected to high pressure and high heat in the presence of a metal catalyst. This results in the production of excess heat and strong penetrating electromagnetic radiation. After the reaction, an analysis of residual gas reveals a variety of hydrocarbons, but it seems unlikely that these products can explain the excess heat. Most of them form endothermically, and furthermore heat production reached 60 W. Overall heat production exceeded any conceivable chemical reaction by two orders of magnitude.
文摘Neutral isotopes and ions of H, He and Li define the chemistry of the early universe by collisional and radiative process, where under low temperature and radiation regime, only neutral species were essential in the cooling mass that gave origin to the first proto star structures. Nevertheless, up to now, in every kinetic model Li is permanently discarded from fundamental reactions due to its extremely low density. Contrarily to these previous models we have developed a novel kinetic model based on two consecutive reactions of Li and LiH with H, in order to generate a recursive process that fit well H2 production to temperatures as low as 200 K, according to the cosmological time at the end of the dark epoch. Our results show how Li and LiH merge as first catalyzers of the H to H2 chemical reaction and permit us to explain the expected abundance of H2 as the main coolant in the early universe as well as in cold regions of the cosmos.
基金Project supported by the Hi-Tech Research and Development Program(863) of China (No. 2002AA601270)
文摘The dectrochemical reduction characteristics of carbon tetrachlofide (CT) were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders' iron and the catalyzed Fe-Cu process was discussed. The results showed that CT was reduced directly on the surface of copper rather than by atomic hydrogen produced at the cathode in the catalyzed Fe-Cu process. The reduction was realized largely by atomic hydrogen in Master Builders' iron. The entire CT in 350 ml aqueous solution with 320 mg/L was reduced to trichloromethane and dichloromethane in 2.25 h when 100 g of scrap iron with Fe/Cu ratio of 10:1 (w/w) were used. Moreover, the reduction rate slowed with time. CT could be reduced at acidic, neutral and alkaline pH from solution by Fe-Cu bimetallic media, but the mechanisms were different. The degradation rate was not significantly influenced by pH in the catalyzed Fe-Cu process; in Master Builders' iron it clearly increased with decreasing pH. The kinetics of the reductions followed pseudo-first order in both cases. Furthermore, the reductions under acidic conditions proceeded faster than that under the neutral and alkaline conditions. The catalyzed Fe-Cu process was superior to Master Builders' iron in treating CT-containing water and this advantage was particularly noticeable under alkaline conditions. The reduction was investigated in the cathode (Cu) and anode (Fe) compartments respectively, the results showed that the direct reduction pathway played an important role in the reduction by the catalyzed Fe-Cu process. The catalyzed Fe-Cu process is of practical value.
文摘A novel technology which combined electrochemical process catalyzed by manganese mineral with electro-assisted coagulation process was proposed in this study. The mineralization of organic pollutant from simulated dye wastewater containing an azo dye Acid Red B(ARB) was experimentally investigated using this method. It was found that the manganese mineral could catalyze the electrochemical process dramatically. The TOC removal percentage of electrochemical treatment catalyzed by manganese mineral was 43.6% while the TOC removal percentage of the process using the manganese mineral alone and using the electrolysis alone were 9.3% and 20.8%, respectively. Moreover, it was found that combined electroxidation with electro-assisted coagulation process could more effectively eliminate ARB. After a period of 180 min electrooxidation and 300 min electroreduction, almost 66.9% of TOC was removed, and the dissolved Mn^2+. could be effectivly removed. The effects of the order of oxidation and reduction, the proper ratio electrooxidation/reduction time, and current density on the removal efficiency were investigated in detail. In addition, a proposed mechanism of manganese-mineral-catalyzed electrooxidation-reduction process was discussed in this paper.
文摘The reduction of the nitrobenzene compounds (NBCs) by the catalyzed Fe-Cu process and the relationship between the electrochemical reduction characteristics of NBCs at copper electrode and reduction rate were studied in alkaline medium(pH=11). The catalyzed Fe-Cu process was found more effective on degradation of NBCs compared to Master Builder's iron. The reduction rate by the catalyzed Fe-Cu process decreased in the following order: nitrobenzene 〉4-chloro-nitrobenzene ≥m-dinitrobenzene :〉 4-nitrophenol ≥2,4-dinitrotoluene 〉2-nitrophenol. The reduction rate by Master Builder's iron decreased in the following order: m-dinitrobenzene ≥4-chloro-nitrobenzene 〉4-nitrophenol 〉2,4-dinitrotoluene ≈nitrobenzene 〉2-nitrophenol. NBCs were reduced directly on the surface of copper rather than by the hydrogen produced at cathode in the catalyzed Fe-Cu process. The reduction was realized by the hydrogen produced at cathode and Fe(OH)2 in Master Builder's iron, It is an essential difference in reaction mechanisms between these two technologies. For this reason, the reduction by the catalyzed Fe-Cu depended greatly on NBC's electron withdrawing ability.
文摘Forced oxidation of calcium sulfite aqueous slurry is a key step for the calcium-based flue gas desulfurization(FGD) residue. Experiments were conducted in a semi-batch system and a continuous flow system on lab scales. The main reactor in semi-batch system is a 1000 ml volume flask. It has five necks for continuous feeding of gas and a batch of calcium sulfite solution/aqueous slurry. In continuous flow system, the main part is a jacketed Pyrex glass reactor in which gas and solution/aqueous slurry are fed continuously. Calcium sulfite oxidation is a series of complex free-radical reactions. According to experimental results and literature data, the reactions are influenced significantly by manganese as catalyst. At low concentration of manganese and calcium sulfite, the reaction rate is dependent on 1.5 order of sulfite concentration, 0.5 order of manganese concentration, and zero order of oxygen concentration in which the oxidation is controlled by chemical kinetics. With concentrations of calcium sulfite and manganese increasing, the reactions are independent gradually on the constituents in solution but are impacted by oxygen concentration. Manganese can accelerate the free-radical reactions, and then enhances the mass transfer of oxygen from gas to liquid. The critical concentration of calcium sulfite is 0.007 mol/L, manganese is 10 -4 mol/L, and oxygen is of 0.2—0.4 atm.
文摘Ammonium perchlorate(APC)is the most common oxidizer in use for solid rocket propulsion systems.However its initial thermal decomposition is an endothermic process that requires 102.5 J·g^-1.This manner involves high activation energy and could render high burning rate regime.This study reports on the sustainable fabrication of CuO nanoparticles as a novel catalyzing agent for APC oxidizer.Colloidal CuO nanoparticles with consistent product quality were fabricated by using hydrothermal processing.TEM micrographs demonstrated mono-dispersed particles of 15 nm particle size.XRD diffractogram demonstrated highly crystalline material.The synthesized colloidal CuO particles were effectively coated with APC particles via co-precipitation by using fast-crash solvent-antisolvent technique.The impact of copper oxide particles on APC thermal behavior has been investigated using DSC and TGA techniques.APC demonstrated an initial endothermic decomposition stage at 242℃ with subsequent two exothermic decomposition stages at 297,8℃ and 452.8℃ respectively.At 1 wt%,copper oxide offered decrease in initial endothermic decomposition stage by 30%.The main outcome of this study is that the two main exothermic decomposition peaks were merged into one single peak with an increase in total heat release by 53%.These novel features can inherit copper oxide particles unique catalyzing ability for advanced highly energetic systems.
基金supported by National 863 High-Tech Research and Development Program of China(No. 2007AA05Z101)
文摘In this article,an efficient,simple and environmentally friendly approach to the synthesis of diacetals(diketals) pentaerythritol using SOH-functionalized ionic liquids(ILs) as catalysts was reported.The ILs show high catalytic activity and reusability with good to excellent yields of the desired products.Hammett method has been used to determine the acidity order of these ionic liquids and the results are consistent with the catalytic activities observed in acetalization reaction.Maximum product yield of 93%was observed on using[PSPy][OTf]as catalyst and it can be reused at least 8 times without obvious activity loss.
基金Projects(51804136,51764016)supported by the National Natural Science Foundation of ChinaProject(U1402271)supported by the Joint Funds of the National Natural Science Foundation of China+2 种基金Project(20181BAB216017)supported by the Jiangxi Provincial Natural Science Foundation,ChinaProject(GK-201803)supported by the Research Fund Program of State Key Laboratory of Rare Metals Separation and Comprehensive Utilization,ChinaProjects(yy2016001,yy2016012)supported by the Research Fund Program of the State Key Laboratory of Pressure Hydrometallurgical Technology of Associated Nonferrous Metal Resources,China。
文摘The mechanism of oxygen pressure acid leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation was investigated in this study.Artificial sphalerite was fabricated with varying amounts of iron content via the sintering of ZnS and FeS and used for the pressure acid leaching experiment.The variations in the potential of the pressure leaching system were investigated by using a self-designed potential autoclave.The results showed that compared to the non-iron sphalerite,there was a violent redox reaction between the 25.70%Fe-artificial sphalerite and dissolved oxygen during the process of pressure leaching;and the catalytic mechanism was attributed to the redox couple Fe^3+/Fe^2+,where Fe3+oxidizes the H2S gas film and the reduced Fe2+state is subsequently oxidized by the dissolved oxygen.Furthermore,the effect of temperature,H2SO4 concentration,and oxygen partial pressure on the artificial sphalerite with different iron contents was studied.The sphalerite samples with iron content were observed to dissolve more easily in sulfuric acid compared to the non-iron samples.Moreover,the activation energy of artificial sphalerite was observed to be lower in the sample with 25.70%iron content(22.26 kJ/mol)compared to that with no iron(32.31 kJ/mol);and the apparent reaction orders were obtained with respect to H2SO4 concentration(1.10 and 1.36)and oxygen partial pressure(1.29 and 1.41),respectively.A comprehensive kinetic model was developed on the basis of the experimental data and the fitted leaching ratio plot;and the kinetic equations for the leaching of sphalerite catalyzed by Fe^3+/Fe^2+self-precipitation were determined.